Owners of Samsung Galaxy Book laptops are facing significant issues following a recent Windows 11 update by Microsoft. The update seems to have caused critical problems, leading to the loss of access to the essential C drive. Users are encountering a message stating “C:is not accessible – Access denied,” preventing them from opening files and running certain applications like Microsoft Outlook, Office apps, and specific web browsers.
Several model numbers, including NP750XGJ, NP750XGL, NP754XGJ, NP754XFG, NP754XGK, DM500SGA, DM500TDA, DM500TGA, and DM501SGA, are believed to be impacted by this issue.
Microsoft has acknowledged the issue, stating that certain Samsung device models are experiencing C drive access loss after installing the February 2026 security update (KB5077181) and subsequent updates. This error restricts file access and application launches such as Outlook, Office apps, web browsers, system utilities, and Quick Assist.
The problem is suspected to be related to Samsung’s Galaxy Connect app, which facilitates screen mirroring, file sharing, and data transfer between Galaxy smartphones and Windows computers. The app has been temporarily removed from the Windows app store until a resolution is implemented.
Samsung has republished a stable previous version of the application to prevent further installations and is working with Microsoft to evaluate solutions for impacted devices. A fix timeline is currently uncertain. Users with Samsung PCs are advised to hold off on updating to Windows 11 versions 24H2 and 25H2 for now.
For those already on Windows 11 versions 24H2 and 25H2, it is recommended to refrain from making any changes until the issue is resolved.